feat: Updates widget message state to support multiple conversations

app/javascript/widget/store/modules/message/mutations.js

@@ -0,0 +1,51 @@
+import Vue from 'vue';
+
+export const mutations = {
+  addMessagesEntry($state, { messages = [] }) {
+    messages.forEach(message => {
+      Vue.set($state.messages.byId, message.id, message);
+    });
+  },
+
+  addMessageIds($state, { messages }) {
+    const messageIds = messages.map(message => message.id);
+    const allIds = $state.messages.allIds;
+    const newIds = [allIds, messageIds];
+    const uniqIds = Array.from(new Set(newIds));
+
+    Vue.set($state.messages, 'allIds', uniqIds);
+  },
+
+  updateMessageEntry($state, message) {
+    const messageId = message.id;
+    if (!messageId) return;
+
+    const messageById = $state.messages.byId[messageId];
+    if (!messageById) return;
+    if (messageId !== message.id) return;
+
+    Vue.set($state.messages.byId, messageId, { ...message });
+  },
+
+  removeMessageEntry($state, messageId) {
+    if (!messageId) return;
+
+    Vue.delete($state.messages.byId, messageId);
+  },
+
+  removeMessageId($state, messageId) {
+    if (!messageId) return;
+
+    $state.messages.allIds = $state.messages.allIds.filter(
+      id => id !== messageId
+    );
+  },
+
+  setMessageUIFlag($state, { messageId, uiFlags }) {
+    const flags = $state.messages.uiFlags.byId[messageId];
+    $state.messages.uiFlags.byId[messageId] = {
+      ...flags,
+      ...uiFlags,
+    };
+  },
+};